1. Field of the Invention
The present invention generally relates to data communication systems and apparatuses and, more particularly, to a data communication system and apparatus for performing sound and information data communication between a plurality of apparatuses (terminal equipment, line connection apparatuses).
As an example of a communication system of this kind, there is known an emergency report system for implementing 119/110 call reception from a subscriber, inter-console monitoring/interruption, fire station/police substation command origination, and radio communication with a dispatched automobile (ambulance, fire engine, police car and the like), 119 being a number dialed in Japan to call a fire station, and 110 being a number dialed to call a police station. Emergency 119/110 call reception from a subscriber, inter-console monitoring/interruption, fire station/police substation command origination, radio communication with a dispatched automobile are major facilities provided in a fire fighting center and police headquarters. In an emergency report system, plural apparatuses (public network switches, report reception consoles, command receiver apparatuses in a fire station/police substation, remote radio base station apparatuses) connect to each other via a switch (PBX) provided in a fire fighting center or the police headquarters and perform communication of sound and information data. Because such an emergency report system is socially important, the quality of high-speed (particularly, reduction of time required to transmit a command), reduction of system size, reduction of time required for delivery, and reduction in cost are demanded by customers, to say nothing of high-quality, high-reliability communication service.
2. Description of the Related Art
FIG. 1A is a schematic diagram showing a construction of an emergency report system according to the related art. Referring to FIG. 1A, the emergency report system comprises a subscriber telephone (TEL) 1, a public (NTT) network 100, a line circuit (LC) 2, a switch (NW) 70 of the NTT network, an emergency report trunk (FPT) 3, a fire fighting center/the police headquarters 200/300, a reception console 40 of emergency reports, a switch (NW) 20 of the fire fighting center/the police headquarters, an emergency report reception trunk (FPI) 23, a command line trunk (LDS) 24, a fire station/police substation 201/301, and a command receiver apparatus 60.
When a subscriber dials 119 using the TEL 1, the call arrives at the switch 20 of the fire fighting center 200 via the switch 70 of the NTT network and the emergency report line, and is accepted by the report reception console 40. The receiver of the report gives a command to a related (near the origination of the report) fire station 201. The command is sent to the command receiver apparatus 60 of the related fire station 201 via the switch 20 and the command line. The command receiver who heard the command dispatches a vehicle (an ambulance, a fire engine or the like) according to the command, so that the subscriber can benefit from timely emergency service for an illness or disaster.
When a subscriber calls 110 using the TEL 1, the call arrives at the switch 20 of the police headquarters 300 via the switch 70 of the NTT network and the emergency report line, and is accepted by the report reception console 40. The receiver of the report gives a command to a related (near the origination of the report) police substation 301. The command is sent to the command receiver apparatus 60 of the related police substation 301 via the switch 20 and the command line. The command receiver who heard the command dispatches a police car or a policeman to the spot according to the command, so that the subscriber can benefit from timely emergency service for a problem or accident. After the dispatch, communication between the vehicles and the reception console 40 is performed through a radio circuit (not shown).
FIG. 1B is a perspective view showing the report reception console. Referring to a FIG. 1B, the report reception console has a line status display unit (LSDISP) 51 for performing realtime display of a line status (unused, call incoming, call proceeding, holdback etc.) of the emergency report line, the command line and the radio circuit; an operation unit 55 for displaying information indicating an emergency call incoming and for performing a call incoming reply operation (button operation); display lamps (LMP) 43, and operation buttons (KEY). Some of the operation buttons 44 are arranged to form a pair with respective display lamps 43 so that a button operation corresponding to the lamp display can be performed quickly. The report reception console further comprises a headset or a handset (HS) used by a reception console manipulator for a call, and a monitor speaker (MSP) for monitoring a radio call sound as it arrives from a radio-equipped vehicle (fire engine, police car or the like).
FIG. 2 shows a signaling system of the emergency report line according to the related art.
Referring to columns of FIG. 2, DC indicates a DC line, and AC indicates an AC line (ringing tone at 16 Hz or the like). The line status of FPT 3 (unused, call originating, call proceeding, a re-ring signal, disconnection) is listed in horizontal columns. For example, in a state where the fire-fighting center DC line is xe2x80x9cunusedxe2x80x9d, line A and line B of FPT 3 are connected to a zero potential (open), and line A of FPI 23 is connected to a zero potential (open) and line B thereof is connected to the ground via a constant resistance. When FPT 3 originates a call by connecting both line A and line B to xe2x88x9248 V, an electric current flows in line B of the FPI 23 so that the call origination by the FPT 3 is detected (that is, a call incoming from the emergency report line is received). Other aspects of the operation proceed similarly.
While the description below mainly concerns the emergency report system involving the fire fighting center, it can also be applied to the emergency report system involving the police headquarters.
FIG. 3 shows a construction of the emergency report system according to the related art.
The emergency report system according to the related art uses the line switching facilities of the switch 20 (a call path switch 22, a call control unit 21), to connect calls between a subscriber, a reception console, a command receiver apparatus, and a radio-equipped vehicle. A detailed description will be given below.
Referring to FIG. 3, the emergency report system comprises the switch main body (NW) 20 of the fire fighting center, reception consoles 401-40n for performing 119 call reception, inter-console monitoring/interruption, origination of a command to a related station, radio communication with radio-equipped vehicles, command receiver apparatuses 601-60m provided in each station, and radio apparatuses (RFU) 41-4k for performing radio communication with dispatched vehicles MS.
The switch main body NW 20 comprises the call control unit (CC) 21 for controlling major facilities (call processing and the like) of the switch main body, the call path switch (NSW) 22 for switching sound and information data, the emergency report reception trunk (FPI) 23 connected to an emergency report line, the command line trunk (LDS) 24 connected to the command receiver apparatus 60, a radio circuit trunk (RLT) 25 connected to RFU 4, a reception console connection package (ATT) 26 connected to the reception console 40, an inter-console monitoring connection package (OTL) 27 for controlling sound monitoring/interruption connection between the reception consoles, and a radio apparatus connection control package (DMC) 28 for connecting the reception console 40 to RFU 4.
The reception console 40 comprises a reception console control package (CTL) 41 for controlling major facilities of the reception console, a lamp/button information processing unit (CBA) 42 for processing lamp information and button information, the reception console operation unit 55, a lamp information display unit (LMP) 43 embodied by an LED or the like, a button operation unit (KEY) 44, a lamp driver (SDA) 45 for lighting an LED that corresponds to lamp information, a button operation discrimination unit (SCA) 46 for discriminating depression of a button and sending button information to CBA42. The reception console 40 provides a sound process unit (SPA) 47 for processing a sound signal, a head set 48 or a hand set (HS) that the reception console manipulator uses, a microphone MIC, a headphone HDP, a call path control package (SPC) 49 for connecting sound between SPA47 and ATT26 and for performing switching control of the call path connected to OTL27 and DMC28, an inter-console monitoring/radio activation package (IFC) 50 for sending an activation signal to OTL27 and DMC28 and for detecting a reply signal, the line status display unit (LSDISP) 51 for displaying line status of the emergency report line, the command line, and the radio circuit on the front panel, and a monitor speaker (MSP) 52 for outputting a radio call sound from the radio-equipped vehicle MS.
A description will now be given of the facilities provided in the reception console. FPI 23 is provided with facilities for detecting a 119 call incoming and notifying the reception console 40 accordingly, facilities for placing a re-ring call from the reception console 40 via the emergency report line (an operation whereby the reception console 40 makes a call using a ringing tone when a subscriber terminates a call), facilities for sending a disconnection signal to the emergency report line in response to a restoration operation of the reception console 40, and facilities for displaying the status of the emergency report line on LSDISP 51 of the reception console 40.
Status information of the emergency report line is sent via a metallic information line 81 to an MDF (Main Distributing Frame), and is distributed to each LSDISP 51 of the reception consoles 401-40n by multiple-connection from the MDF, so that all the reception consoles 401-40n can monitor the status of the emergency report line in realtime. The status of the emergency report line is displayed as follows:
unused: unlighted;
call incoming: 120INT (blinking);
call proceeding: continuously lighted
holdback: 60INT.
LDS 24 is provided with facilities whereby it is captured via NSW 22 in response to an operation in the reception console, so as to send an activation signal (a ringing tone) to the command receiver apparatus 60, facilities for detecting a reply (a loop) from the command receiver apparatus 60, and sending reply information to the reception console 40, facilities for sending command sound from the reception console 40 to the command receiver apparatus 60, and facilities for displaying a status of the command line on the LSDISP 51 of the reception console 40.
Status information of the command line is distributed to each LSDISP 51 of the reception consoles 401-40n via the metallic information line 81 and MDF, so that all the reception consoles 401-40n can monitor a status of all the command lines in realtime. The status of the command line is displayed as follows:
unused: unlighted;
calling: 120INT;
command proceeding: continuously lighted
RLT 25 is provided with facilities whereby it is captured via NSW 22 in response to an operation in the reception console, so as to call a radio-equipped vehicle, facilities for notifying the reception console 40 of a call incoming via RFU4, and facilities for displaying a status of the radio circuit on LSDISP 51 of the reception console 40.
Status information of the radio circuit is distributed to each LSDISP 51 of the reception consoles 401-40n via the metallic information line 81 and MDF, so that all the reception consoles 401-40n can monitor a status of all the radio circuits in realtime. The status of the radio circuit is displayed as follows:
unused: unlighted;
call incoming: 120INT;
call proceeding: continuously lighted
RLT25 is further provided with facilities for sending a radio call sound from a radio-equipped vehicle MS to MSP 52 of the reception console 40. Radio call sound is sent via a metallic information line 82 to MDF, and is distributed to each MSP 52 of the reception consoles 401-40n by multiple-connection from MDF, so that all the reception consoles 401-40n can monitor the radio call sound from radio-equipped vehicles.
OTL 27 implements sound monitoring/interruption connection between the reception consoles, and is provided one for each reception console to provide one call path in NSW 22. When an inter-console monitoring operation is performed at the reception console 40n while a subscriber and a manipulator or operator of the reception console 401 is speaking over the phone, an activation signal is sent from IFC 50n to OTL 27n under the control of CTL41n. With this, a call channel is formed with respect to SPC 491 of the monitored console 401 via NSW 22, so that the manipulator of the reception console 40n can perform inter-console monitoring of the sound of the call via SPC 491-OTL 271-NSW22-OTL 27n-SPC 49n. A detailed description will be given with reference to FIG. 7.
DMC 28 connects the reception console 40 to RFU 4. DMC 28 is provided one for each reception console to provide one call path in NSW 22. For example, when an operation of originating a call to a radio-equipped vehicle is performed in the reception console 401, an activation signal is sent out from IFC 501 to DMC 28 under the control of CTL 411, and a call path connected to RFU 4 is formed via RLT 25, so that radio communication becomes possible. A detailed description will be given with reference to FIG. 10.
ATT 26 is provided with facilities for sending 119 call incoming information from FPI 23 and radio call incoming information from RLT 25 to the reception console 40, facilities for sending button depression information occurring in the reception console operation unit 55 to FPI 23, LDS 24, RLT 25 or the like, facilities for relaying a sound signal between these components.
CTL 41 is provided with facilities for exchanging lamp information and button depression information with ATT 26, facilities for sending activation information from IFC 50 to OTL 27/DMC 28 in inter-console monitoring/interruption and in radio call origination, and facilities for causing SPC49 to perform call path switching operation in inter-console monitoring.
FIGS. 4A and 4B show information interface between CTL 41 and ATT 26 according to the related art. As described above, lamp information indicating detection of an incoming urgent call, for example, is sent from ATT 26 to CTL 41, and, in response to that, button information indicating a call receiving operation, for example, is sent from CTL 41 to ATT 26.
FIG. 4A shows a format of the lamp information. One ROW of the lamp information comprises 8 bits, and each bit except the highest flag bit B7 corresponds to one lamp (LED) of the reception console operation unit 55. The lamp information is provided for all of the display lamps 43 of the operation unit 55. For example, the lamp information ROW0-ROWn is provided. By setting the highest bit B7 of ROW0 to 0 and setting each highest bit B7 of ROW1-ROWn to 1, the lamp information ROW0 at the head can be identified.
FIG. 4B shows a format of information data communication between CTL 41-ATT 26. Bit serial transfer of lamp information is performed from ATT 26 to CTL 41. The lamp information ROW0 is sent first. One transmitted frame of the lamp information ROW0 comprises a total of 11 bits including a start bit xe2x80x9cSTxe2x80x9d, lamp information bits xe2x80x9cB0-B6xe2x80x9d, a flag bit xe2x80x9cB7xe2x80x9d, a parity bit xe2x80x9cPAxe2x80x9d, and a stop bit xe2x80x9cSTxe2x80x9d. The transmission time for 1 bit is 32 xcexcs, so that the transmission time for a total of 11 bits is 352 xcexcs.
After a pause xcex1 (which depends on the system), the lamp information ROW1 is sent. In this way, the lamp information ROW0-ROWn is sent, thus completing the first sequence of lamp information transmission. Similarly, the second and subsequent sequences of lamp information transmission is performed. For example, if the lamp information bit xe2x80x9cB2xe2x80x9d of ROW0 is always set to 1, the corresponding LED is lighted continually. If bit xe2x80x9cB2xe2x80x9d is continually set to 0, for example, the corresponding LED is continually extinguished. If bit xe2x80x9cB2xe2x80x9d is set to 1 and 0 alternately, the corresponding LED blinks.
Button information is sent from CTL 41 to ATT 26. One transmitted frame of button information comprises a total of 11 bits including a start bit xe2x80x9cSTxe2x80x9d, code information bits xe2x80x9cB0-B7xe2x80x9d of the button, a parity bit xe2x80x9cPAxe2x80x9d, a stop bit xe2x80x9cSTxe2x80x9d. The transmission time for 1 bit is 32 xcexcs, so that the transmission time for a total of 11 bits is 352 xcexcs. After a pause of about 9.65 ms, altogether producing a time span of 10 ms, the second and subsequent sequences of button information transmission is performed. The code information bits xe2x80x9cB0-B7xe2x80x9d of the button is the information obtained by encoding the depression of the button of the operation unit 55. A maximum of 256 buttons can be distinguished from each other in this example. In this way, code information of a button is sent at a 10 ms period. While a button is being depressed, the code information is sent in succession, and, when the button is let go, the code information having all bits set to 0 is sent.
FIG. 5 shows a communication protocol of the command line according to the related art. When a command receiver apparatus activation button of the reception console operation unit 55 is depressed, LDS 24 sends an activation signal (a ringing tone) to the command receiver apparatus 60. The command receiver apparatus 60 detects the ringing tone so as to send back a reply (a loop) automatically. When LDS24 detects the loop, it sends out an activation tone. The command receiver apparatus 60 detects the activation tone so as to activate a sound amplifier. When the manipulator sends a command via LDS 24 subsequently, the command sound is output by a loud speaker of the command receiver apparatus 60 so as to be heard by a command receiver. When the command has been processed, an operation for restoration from command is performed such that a restoration tone is sent from LDS 24. The command receiver apparatus 60 detects the restoration tone so as to deactivate the sound amplifier and sends back a restoration reply (loop disconnection). Although not illustrated, a call origination operation from the command receiver apparatus 60 to the reception console 40 may also be performed.
A description will now be given of major facilities provided in the emergency report system according to the related art, including 119 call reception, inter-console monitoring/interruption, fire station command, and radio communication.
FIG. 6 shows a 119 call reception operation according to the related art.
A 119 call from the TEL 1 arrives at FPI 23 by LC 2-public network 100-FPT 3-the emergency report line ((1) of FIG. 6). When call incoming is detected on the emergency report line, FPI 23 sends out call incoming information (lamp information). The lamp information is sent to CTL 41 of the reception console 40 via a control channel-CC 21-ATT 26 of NSW 22 ((2) of FIG. 6). CTL 41 lights the reception button lamp 43 of the reception console operation unit 55 via CBA 42-SDA 45, according to the call incoming lamp information, and also sounds a call incoming buzzer (not shown).
When the reception console manipulator depresses the reception button 44 of the operation unit 55, the button information is sent via SCA 46-CBA 42-CTL 41-ATT 26 to the switch main body (CC 21) ((3) of FIG. 6). A call incoming reply signal is returned from FPI 23 to FPT 3 ((4) of FIG. 6), and a call path (call channel) is formed between the subscriber and the reception console manipulator ((5) of FIG. 6), so that the call can proceed.
When the reception console manipulator depresses a disconnection button of the operation unit 55 at the end of the call, the button information is sent via SCA 46-CBA 42-CTL 41-ATT 26 to the switch main body ((3) of FIG. 6). The call disconnection signal is sent from FPI 23 to FPT 3 ((6) of FIG. 6), so that the emergency report line is restored.
Status information (call incoming, unused etc) of the emergency report line is sent from FPI 23 via the metallic information line 81 to the reception consoles 401-40n so that all the reception consoles 401-40n can monitor a status of the emergency report lines in realtime.
FIG. 7 shows an inter-console monitoring/interruption operation according to the related art. Inter-console monitoring enables monitoring the call contents of the reception console 401 in which a 119 call is proceeding, from another reception console 40n. The monitored contents are used to back up the report reception console 401 by, for example, originating a command to the related station. Inter-console interruption enables call interruption to the reception console 401 in which a 119 call is proceeding, from another reception console 40n. A description will now be given of inter-console monitoring and call interruption performed by the reception console 40n with respect to the reception console 401 receiving a 119 call.
It is assumed that a call path is formed as described above between a subscriber and the reception console 401, and a call is proceeding between the subscriber and the reception console manipulator ((1) of FIG. 7). When the manipulator of the reception console 40n depresses an inter-console monitoring button 44 of the operation unit 55n, the button information is supplied to CTL 41n via SCA 46n-CBA 42n. An inter-console monitoring activation SD point of IFC 50n is turned ON under control of CTL 41n, and OTL 27n is activated ((2) of FIG. 7). When the call origination is detected, OTL 27n performs hot line connection using an extension (call connection not requiring a dial number) to OTL 271 of the reception console 401 ((3) of FIG. 7). A call path is formed between SPC 49n of the reception console 40n and SPC 491 of the reception console 401, so that the 119 call contents of the reception console 40n can be monitored by the reception console 40n ((4) of FIG. 7).
When the operation unit interruption button 44n of the reception console 40n is depressed, the button information is supplied to CTL 41n via SCA 46n-CBA 42n, and an interruption relay in SPC 49n (not shown) is turned ON under the control of CTL 41n, so that the reception console 40n can interrupt the 119 call in the reception console 401 ((5) of FIG. 7). In this case, call interruption in SPC 491 is performed by addition of the sound signal.
Restoration from inter-console monitoring/interruption is performed as follows. By depressing the disconnection button 44n of the operation unit of the reception console 40n, the button information is supplied to CTL 41n via SCA 46n-CBA 42n, and an inter-console monitoring activation SD point is turned OFF under the control of CTL 41n, so that the call path between the reception console 40n and the reception console 401 is terminated, thus restoring from inter-console monitoring/interruption connection.
FIG. 8 shows a station command operation.
A station command is given to an ambulance or a fire engine of a fire station according to the contents of the 119 call report. The command is issued when the reception console manipulator or operator has selected a target station. When a station button of the reception console operation unit 551 is depressed, button information is sent to the switch main body (CC 21) via SCA 461-CBA 421-CTL 411-ATT 26 ((1) of FIG. 8). CC 21 captures LDS 24 for a command recipient station ((2) of FIG. 8), and the command receiver apparatus 60 is activated by LDS 24. When LDS 24 detects a reply from the command receiver apparatus 60, a call path is formed to establish a connection SPA 471-ATT 26-NSW 22-LDS 24, so that the command sound of the reception console manipulator is heard at the command receiver device 60 ((3) of FIG. 8). Plural stations may be simultaneously selected as destinations of the station command.
FIG. 9 illustrates a station command sequence of the emergency reporting system according to the related art. When the activation button of a station is depressed, LDS1-LDSm corresponding to respective stations are captured successively by CC 21, so that the communication protocol of the command line described above with reference to FIG. 5 is executed between LDS1-LDSm and the command receiver apparatuses 601-60m. Conventionally, a relatively long time was needed for capturing LDS1-LDSm by NSW 22. When the sound amplifier of the command receiver apparatuses 601-60m is activated, the command sound is delivered thereto all at once. After the command has been sent, disconnection of the station command is performed by depressing the disconnection button of the reception console operation unit 55
FIG. 10 shows a radio communication operation according to the related art. Radio communication provides back-up for dispatched automobiles (fire engines, ambulances) after the station command has been originated. Call origination to a radio-equipped vehicle is performed such that a radio selection button of the reception console operation unit 551 is depressed, so that the button information is supplied to CTL 411 via SCA 461-CBA 421. A radio activation SD point of IFC 501 is turned ON and DMC 28 is activated under the control of CTL 411 ((1) of FIG. 10). DMC 28 connects to RLT 25 by a hot line connection (FIGS. 24-2), so that a call path is formed to connect the reception console 401-SPA 471-SPC 491-DMC 28-NSW 22-RLT 25 ((3) of FIG. 10). Radio communication occurring in this case with a vehicle is press talking because one frequency is used for two-way communication. When a press talk button of the reception console operation unit 551 is depressed, the button information is supplied to CTL 411 via SCA 461-CBA 421, a press SD point of IFC 501 is turned ON under the control of CTL 411, and the press information is transmitted to RFU 4.
A radio call incoming from a vehicle is recognized such that a call incoming signal from RFU 4 is displayed on each LSTDISP 51 of the reception consoles 401-40n via RLT 25xe2x80x94the metallic information line 81 ((4) of FIG. 10), and radio call sound from the vehicle is delivered as-is to each MSP 52 of the reception consoles 401-40n via RLT 25xe2x80x94the metallic sound line 82 ((5) of FIG. 10). A reply to this call incoming is performed by depressing the radio selection button so as to capture corresponding RLT 25, as described above with respect to a radio call origination operation.
FIGS. 11A and 11B illustrate system capacity of the emergency reporting system according to the related art.
FIG. 11A shows an implementation of a switch (equivalent to Fujitsu model E3160D) according to the related art. One rack includes a shelf of five steps, and each shelf may have 16 boards mounted thereon. The hatch-toned portion of FIG. 11A shows an arrangement of function units when a total of 14 reception consoles are mounted. CC, CPNW indicate function units in the control system, LT indicates a function unit in the interface system, and LT (console) indicates a function unit in the console interface system.
In the LT unit, NW00-NW03 indicate network numbers identifying switches, and HW00-HW31 are network highway numbers. A total of 32 channels (time slots) can be accommodated in one HW. According to the system of the related art, the 7-rack 4NW construction is needed when the 14 reception consoles are mounted, so that a total of 27 LT units are mounted.
FIG. 11B shows the number of MDF cables according to the related art. A compartment of FIG. 11B represents an MDF terminal board. Five MDF cables, each equivalent to 50-pin connector, can be accommodated in one terminal board. In the system according to the related art, MDF cables equivalent to a total of 750 50-pin connectors were needed.
As described above, call connection between apparatuses is effected by line switching via NSW 22 according to the related art, resulting in a relatively large system capacity. To be concrete, because inter-console monitoring/interruption is performed via NSW 22, SPC 49 which provides an interface between the reception console and NSW, IFC 50 for activation, OTL 27 for inter-console monitoring are necessary for each reception console. Because radio communication is performed via NSW 22, DMC 28 for radio connection that provides an interface between the reception console and NSW is necessary for each reception console. Accordingly, the system capacity largely depends on the number of reception consoles. When the number of reception console increases, requests from customers for system size reduction cannot be met.
Because the number of connection packages increases with an increase of the number of reception consoles, the number of cables and MDF terminals also increase with that, thus causing a period of time required for the installation to be extended. To be concrete, display of line statuses including emergency, command, radio on the display of the reception console is effected by multiple connections to the line status display unit 51 of each reception console via the metallic information line 81 and MDF. Therefore, the number of cables and MDF terminals increases depending on the number of lines, and the number of reception consoles. Display of radio call incoming in the reception console, and delivery of the radio call sound are effected by multiple connection to each reception console (LDSISP 51, MSP 52) via the metallic information line 81, the metallic sound line 82 and MDF. Therefore, the number of cables and MDF terminals increases depending on the number of radio circuits, and the number of reception consoles.
Speedups of a station command operation, which is one of the major facilities provided by the emergency reporting system, is known as the most important task. According to the above system of the related art, connection to a station is effected by a call connection process of the switch main body, so that the connect time to a station largely depends on a call connection process time of the switch main body. In particular, when a command is to be originated to plural command receiver devices simultaneously, a relatively heavy load tends to be imposed on the switch main body (CC 21), causing the connect time of NSW 22 to increase significantly.
Accordingly, a general object of the present invention is to provide a data communication system in which the aforementioned problems are eliminated.
Another and more specific object of the present invention is to provide a communication system provided with a simple and flexible network construction in which high-speed data communication between terminals is easily performed.
The aforementioned objects can be achieved by the first invention which provides a data communication system comprising: a plurality of terminal apparatuses for periodically transmitting data, and for retrieving desired data accommodated in at least one time slot in received multiplex data; and a data storage and distribution apparatus for subjecting received data from said plurality of terminal apparatuses to time division multiplexing so as to produce time slots each corresponding to a respective one of said plurality of terminal apparatuses, reproducing resultant multiplex data, and distributing the multiplex data to said plurality of terminal apparatuses.
According to the second invention, the desired data may be one of sound data and information data.
A description will be given, with reference to FIG. 12B, of sound data flow according to a construction of the data communication system of the present invention.
As to terminal apparatuses #1-#n on both sides, apparatuses identified by the same numerals are identical to each other. FIG. 12B is intended to facilitate understanding of upstream sound data and downstream sound data.
Each of the terminal apparatuses #1-#n transmits respective sound data A-N periodically. The only requirement is that each of the sound data A-N is output at a predetermined period. It is not required that the sound data A-N produce successive phase shifts. After having subjected all received sound data A-N from terminal apparatuses to time division multiplexing to accommodate it in time slots allocated for respective terminals, a data storage and distribution device 30 reproduces the sound data and distributes the same between the terminal apparatuses #1-#n. Each of the terminal apparatuses #1-#n retrieves one or a plurality of time slots of sound data from multiplex data MV in the received frame addressed to itself, so that sound data is exchanged between terminal apparatuses #1-#n. To describe the operation more concretely, for example, terminal apparatus #2 retrieves sound data A of terminal apparatus #1, and terminal apparatus #1 retrieves sound data B of terminal apparatus #2, so that a call can proceed between terminal apparatus #1 and terminal apparatus #2. The other terminals operate similarly. Thus, practically, arbitrary n:n call path connection is possible.
Besides, such call path switching facilities can be realized by simple firmware control whereby each terminal changes the setting for retrieval of time slots. Call path switching can be flexibly operated using a simple network construction. Diverse types of calls can proceed at any time between terminal apparatuses without requiring the circuit switching facilities (NSW 22, CC 21) of the system of the related art. Thus, high-speed communication between terminals is made possible using a simplified system. According to the invention, a call path interface is provided so as to be common to all apparatuses, so that the capacity and cost of the communication system is reduced.
Needless to say, information data (instead of sound data) communication may also be performed according to a method of FIG. 12B.
The aforementioned objects can also be achieved by the construction of the third invention shown in FIG. 12A. The data communication system according to the third comprises: a plurality of terminal apparatuses for carrying information in at least one time slot of fixed-length transmission frame assigned to the terminal apparatus and periodically transmitting the transmission frame, and for retrieving desired data accommodated in at least one time slot in fixed-length received multiplex information data; and a data storage and distribution apparatus for subjecting reception frames received from said plurality of terminal apparatuses to a logical sum operation in such a manner as to maintain bit-to-bit correspondence, reproducing the sum, and distributing the sum to said plurality of terminal apparatuses.
A description will be given, with reference to FIG. 12C, of the flow of information data according to the third invention.
Each of the terminal apparatuses #1-#n carries information data in one or a plurality of time slots of fixed-length transmission frames allocated to itself, so as to transmit the information data periodically. A data storage and distribution apparatus obtains a logical sum of all received frame data from the terminal apparatuses, maintaining bit-to-bit correspondence, so as to reproduce and distribute the sum between the terminal apparatuses #1-#n described above. Each of the terminal apparatuses #1-#n retrieves information data in one or a plurality of time slots from the multiplex data RD of fixed-length reception frames allocated to itself. Thus, diverse information data exchange can proceed between terminal apparatuses.
To describe the operation concretely, diverse communication path connection methods are available.
For example, terminal apparatus #1 carries information data axe2x80x2 (0 for the other transmission slots) in the first transmission slot allocated to itself, and transmits the information data accordingly. Terminal apparatus #2 carries information data bxe2x80x2 (0 for the other transmission slots) in the second transmission slot allocated to itself, and transmits the information data accordingly. Each transmission frame is subject to logical sum by the data storage and distribution apparatus, maintaining bit-to-bit correspondence. The data storage and distribution apparatus also reproduces the sum. In this example, the downstream frame is such that the first slot data a=axe2x80x2, and the second slot data b=bxe2x80x2. Accordingly, on the downstream side, terminal apparatus #1 retrieves information data b from the second reception slot, and terminal apparatus #2 retrieves information data a from the first reception slot so that information data communication between the terminal apparatuses #1 and #2 is made possible. This means that information data exchange described with reference to FIG. 12B is possible according to the third invention. Thus, information data originated in a given terminal apparatus (status data, notification data) can be referred to by any other terminal apparatus.
Alternatively, for example, terminal apparatus #1 carries information data bxe2x80x2 (0 for the other transmission slots) addressed to terminal apparatus #2 in the second transmission slot and transmits the information data accordingly. Terminal apparatus #2 carries information data axe2x80x2 (0 for the other transmission slots) addressed to terminal apparatus #1 in the first transmission slot and transmits the information data accordingly. The first slot data of the downstream frame a=axe2x80x2, and the second slot data b=bxe2x80x2. Accordingly, on the downstream side, terminal apparatus #1 retrieves information data a addressed to itself from the first reception slot for itself, and terminal apparatus #2 retrieves information data b addressed to itself from the second reception slot for itself so that information data communication between terminal apparatuses #1 and #2 is made possible. Thus, information data (command data, response data, notification data) can be directly written in the time slot for the destination terminal apparatus according to the construction of the third invention.
In actual use, diverse data communication is possible by using one of the above-described two information transfer methods. In this case, when specified bits of each upstream frame is set to 1 and 0, respectively, a corresponding bit of a downstream frame is set to 1 (logical OR output). The details of the communication method will become clearer by the description of the embodiments that follows.
According to the fourth invention, each of said plurality of terminal apparatuses may periodically transmit sound data and retrieves desired sound data accommodated in at least one time slot in received multiplex sound data, and said data storage and distribution apparatus may subject sound data received from said plurality of terminal apparatuses to time division multiplexing so as to produce time slots each corresponding to a respective one of said plurality of terminal apparatuses, and reproduce resultant multiplex data so as to distribute the same to said plurality of terminal apparatuses.
According to the data communication system of the fourth invention, information data communication facilities according to the system of FIG. 12C and sound data communication facilities according to the system of FIG. 12B are combined. Thus, as shown in FIG. 12A, sound and information data communication can be efficiently performed by a simple network construction and firmware control.
The aforementioned objects can also be achieved by the fifth invention which provides a data storage and distribution apparatus for use in a data communication system in which a plurality of terminal apparatuses perform data communication with each other via said data storage and distribution apparatus, wherein said data storage and distribution apparatus subjects data periodically received from said plurality of terminal apparatuses to time division multiplexing so as to produce time slots each corresponding to a respective one of said plurality of terminal apparatuses, reproduces resultant multiplex data, and distributes the multiplex data to said plurality of terminal apparatuses.
The aforementioned objects can also be achieved by the sixth invention which provides a data storage and distribution apparatus for use in a data communication system in which a plurality of terminal apparatuses perform data communication with each other via said data storage and distribution apparatus, using transmission frames of a common format, wherein
said data storage and distribution apparatus subjects frame data received from said plurality of terminal apparatuses to time division multiplexing, reproduces resultant multiplex data, and distributes the multiplex data to said plurality of terminal apparatuses.
The aforementioned objects can also be achieved by the seventh invention which provides a terminal apparatus for use in a data communication system in which a plurality of said terminal apparatuses perform data communication with each other via a data storage and distribution apparatus accommodating said plurality of said terminal apparatuses, wherein
said terminal apparatus periodically transmits data and retrieves desired data accommodated in at least one time slot of multiplex received data.
According to the eighth invention, each of said terminal apparatuses may comprise: an emergency report trunk apparatus for connecting to an emergency report line of a public network; a reception console apparatus for receiving an emergency report of a subscriber; a command line interface connected to a command receiver apparatus provided at locations including a fire station and a police station; and a radio circuit interface for connecting to a remote radio base station apparatus.
Objectives such as reduction of station command time, reduction of system capacity, reduction of volume of MDF and connection cables, reduction of a time required for delivery, and reduction of cost are achieved at one sweep by applying the data communication system according to the eighth invention to an emergency report system. The details will become clearer by the description of the embodiments to follow.
The data communication system may further comprise a plurality of reception console apparatuses, wherein a first reception console of said plurality of reception consoles retrieves sound data exchanged between said emergency report reception trunk apparatus and a second reception console of said plurality of reception consoles.
Accordingly, inter-console monitoring facilities in an emergency report system are realized by a simple construction and firmware control.
According to the tenth invention, sound data from said first reception console may be retrieved by at least one of said emergency report reception trunk apparatus and said second reception console.
Accordingly, inter-console monitoring/interruption facilities in an emergency report system are realized by a simple construction and firmware control.
According to the eleventh invention, the data communication system may further comprise a plurality of reception consoles, wherein each of said plurality of reception consoles displays on a display unit information relating to an operating condition of at least one reception console apparatus, said information being included in multiplex received information data.
Therefore, according to the eleventh invention, the line status information, which is distributed by the metallic information line 81 between the reception console display units according to the related art, is put together in the form of multiplex information data RD. The multiplex information data RD is distributed efficiently between the reception console apparatuses in real time and displayed at each reception console display unit.
The aforementioned objects can also be achieved by the twelfth invention which provides a data switching apparatus comprising: an emergency report reception trunk apparatus for connecting to an emergency report line of a public network; a reception console interface for connecting to a reception console for receiving an emergency report from a subscriber; a radio circuit interface apparatus for connecting to a remote radio base station apparatus; a sound data storage and distribution apparatus for subjecting sound data periodically received from a plurality of peripheral apparatuses to time division multiplexing so as to produce time slots each corresponding to a respective one of said plurality of peripheral apparatuses, reproduces resultant multiplex data, and distributes the multiplex data to said plurality of peripheral apparatuses.
Accordingly, the data exchange apparatus according to the twelfth invention is reduced in size and can be installed at a reduced cost and in a reduced period of time. Moreover, the installed apparatus operates so as to provide high performance and high reliability.
According to the thirteenth invention, each of said plurality of peripheral apparatuses may periodically output externally input sound data to said sound data storage and distribution apparatus, retrieve sound data accommodated in at least one time slot in multiplex sound data from said sound data storage and distribution apparatus so as to synthesize the sound data, and output resultant synthesized sound data to one of a connection line and the reception console.
Accordingly, a common sound connection interface of a simple construction can accommodate various peripheral apparatuses (an emergency report reception trunk, a reception console connection package and the like) connected to the sound data storage and distribution apparatus. Each peripheral apparatus can exchange a desired sound signal (sound data) with an external apparatus. Synthesis of sound data is easily implemented by addition of the sound data.
According to the fourteenth invention, the data switching apparatus may further comprise a line switching unit including a call controller and a call path switch provided between an emergency report reception trunk and a reception console interface apparatus, said line switching unit notifying the reception console interface apparatus of call incoming of an emergency call arriving via the emergency report reception trunk apparatus, and capturing an unused line in accordance with a call transfer request from the reception console interface apparatus so as to transfer the emergency call to a call transfer destination.
In actual operation of the emergency report system, an incoming call occurring on an emergency report line may be transferred to a related third party (for example, to utilities). The emergency report line operated such as that may continue to be accommodated in the line switching facilities according to the related art.